They're all good, they have advantages,
Fast charge refers to high power DC charging. It uses the charging interface of the DC charging pile to convert the alternating current of the grid into direct current, which is transmitted to the fast charging port of the electric vehicle, and the electric energy is directly charged into the battery. It can be charged up to 80% in as little as half an hour.
Slow charge refers to AC charging. It is the charging interface of the AC charging pile, which inputs the alternating current of the grid into the slow charging port of the electric vehicle, converts the alternating current into direct current through the charging machine inside the car, and then inputs the battery to complete the charging. The average car takes six to eight hours to recharge its battery.